Hello, I am currently trying to trick my Mac into thinking the external drive I would like to put Windows 10 on is internal. I have the external drive (Samsung X5) erased and formatted as DOS, and plugged in and running on the Mac OS. For some reason, I do not see the drive as an option to select when I use the drop down menu under USB and Bluetooth. My understanding is that the drive should show up along with the settings in this selection, but is clearly not there. Any suggestions for troubleshooting would be greatly appreciated. Sorry I am amateur when it comes to this Thank you!